Means for adjusting driving components of sewing machines



Feb. 3, 1970 H. WENZ ET AL 3,492,959

MEANS FOR ADJUSTING DRIVING COMPONENTS OF SEWING MACHINES Filed Nov. 20, 1968 Fig. 7

Fig.2 Fig. 3

INVENTORS: fifffiffr Wf/YZ A 70 United States Patent 3,492,959 MEANS FOR ADJUSTING DRIVING COMPONENTS OF SEWING MACHINES Herbert Wenz and Heinrich Berg, Kaiserslautern, Germany, assignors to G. M. Pfatf AG, Kaiserslautern, Germany, a firm Filed Nov. 20, 1968, Ser. No. 777,256

Claims priority, application Germany, Nov. 25, 1967,

46 Int. Cl. Db 89/00, 57/14 US. Cl. 112-220 2 Claims ABSTRACT OF THE DISCLOSURE Background of the invention The present invention relates to adjusting means for sewing machines. More in particular the invention is concerned with means for the mutual setting of pivotally con nected or linked driving components of a sewing machine.

It is an object of the invention to improve the possibilities of adjustment of related parts of a sewing machine in a manner that various adjusting operations can be undertaken in a simple manner without expensive auxiliary means.

In accordance with the invention the problem is solved in that on one structural component which is rigidly connected to one of the driving members a slot is provided extending perpendicularly to the direction of its movement, the width of which corresponds to the diameter of a bore provided in an adjacent component which is stationary with respect to the housing, and where the slot registers with the bore in one predetermined position of the movable component.

By these means it is achieved in addition to the exac setting of the angular position of the arm shaft to obtain flawless securing of the firmly positioned machine components against unintentional changes in their position during the setting operation.

Owing to this measure it is possible to set up or determine not only a single, but in practice each one of the different setting positions of the drive components, in that for each desired angular position of the arm shaft a particular bore associated with this angular position is provided in a component which is rigidly fixed relative to the housing.

Brief description of the drawings Further features and objects will become apparent from the embodiment illustrated in the accompanying drawings, in which:

FIG. 1 shows a longitudinal section through the head of a sewing machine and of the part of the work plate disposed below it, with non-essential components omitted,

FIG. 2 shows a structural component of the invention which is rigidly supported in the drawing, and

FIG. 3 shows a component in accordance with the invention which is movable.

Description of a preferred embodiment In the head 1 of the sewing machine the arm shaft 2 is journalled at the end of which that extends into the head 1 a crank 3 is secured by means of a pin or the like. A stud 4 is secured to the crank 3 and on it a thread lever 5 is journalled, which is only partly shown, as well as a connecting bar 6. The other end of the crank stud 4 is received in a supporting disk 7 which is journalled by means of a pin 8 in a bearing disk 9 supported on a dead head 10 of the head 1. A cover 11 threadedly secured to the head 1 closes the structural components in the head toward the outside.

A needle bar stud 12 is journalled in the connecting bar 6 which is securely clamped onto a needle bar 13. The latter is guided in bearings 14 of a carrier 15 which in a suitable manner is journalled or secured in the sewing machine. The needle bar 13 thus has a drive connection which is unchangeable with respect to its phase of movement relative to the arm shaft 2. i

The needle bar 13 supports at its lower end a needle 16 which cooperates in a known manner with a looper 18 arranged below the fabric supporting and work plate 17 of the sewing machine. The looper 18 is connected by a clamping connection, not shown, as well as by way of gears with a shaft 19 that is journalled below the work plate 17, which shaft in turn is in driving connection with the arm shaft 2 by means of driving components, not shown.

Several bores 20, 21 and 22 of equal diameter are provided in the support plate 9. Suitably these bores are disposed at the same radial distance with respect to the center axis of the bearing plate 9, such as, for example, bores 20 and 21. They may of course also be arranged at different radial distances with respect to the center axis of the bearing plate 9, especially when they are at small angular distances from one another, such as, for example, bores 21 and 22.

The supporting disk 7 has a slot 23 whose center plane of symmetry extends radially to the axis of rotation of the supporting disk 7 and whose width corresponds to the diameter of the bores 20, 21 and 22.

The bores 20, 21 and 22 serve for three different adjusting positions of the driving component of the sewing machine. For this purpose they are each arranged in such an angular position upon the support or bearing plate 9 that in that position of the sewing machine in which its axis at any time is disposed in the central plane of symmetry of the slot 23, a definite position of setting or adjustment is obtained that is coordinated with one of the bores 20, 21 or 22.

The bore 20 is intended for the adjustment of the looping stroke of the looper 18, while bore 21 indicates the upper dead point of the needle bar 13 and thus the setting for the phase location of the zig-zag cam of the machine, and finally bore 22 indicates the position for a further adjustment. Suitably appropriate markings can be provided upon the bearing plate 9 alongside the individual bores 20, 21 and 22 which indicate their specific setting coordination.

For adjusting the sewing machine the cover 11 is removed and the drive components of the machine are turned manually until the slot 23 in the supporting disk 7 registers with the desired bore 20, 21 or 22 in the bearing plate 9. This position is fixed by insertion of a gauge plug or a simple machine drill, which is of the same diameter as the bores, into the particular bore 20, 21 or 22 and the slot 23. Now the desired setting or adjustment can be undertaken. Thus, for example, the gauge plug is inserted through the bore 20 and the slot 23 for setting the angular position of the looper in relation to the arm shaft 2, and the point of the looper after releasing its clamped Patented Feb. 3, 1970 connection is set to the center line of the needle 16.

The remaining adjustments to be made with the bores 21 and 22 are effected in an analogous manner.

The provision of the slot 23 in the supporting disk 7 in lieu of a bore having the same diameter provided radially of the axis of rotation of the supporting disk 7 at the same distance as the bores 20 and 21, afiords the advantage that differences which are caused by production tolerances can be compensated. Besides, it is possible by these means to utilize bores for adjustment purposes which are arranged at a difierent radius (bore 22) in the bearing plate 9, Without it becoming necessary that the supporting disk 7 is provided with a separate bore suited for the purpose.

' Having described the invention with reference to the embodiment illustrated in the drawings, what we claim is:

1. In a sewing machine having a housing, a rotatable arm shaft in said housing, a crank presenting a crank stud disposed on said arm shaft, a needle bar, a link connecting said needle bar to said crank stud, a loop taker below said needle bar, means for mutually adjusting the relative position of components of said machine comprising,

a rotatably mounted supporting disk operably connected ,4 v ndr i ha e t o e ttsa s1n le ba an Said 1? taker, a slot in said supporting disk extending perpendicu larly to its path of movement, a stationary bearing part mounted in said housing adjacent said supporting disk and having at least one bore therein, said slot having a width corresponding to the diameterof said bore wherein for a predetermined position-of said supporting disk said slot covers said bore whereby, the timing of said at least oneof said needle bar and said loop taker can be readily set. I

2. 4 Means in accordance with claim 1, wherein said bearing part is mounted inside the head of said housing and means mounting said supporting disk on said bearing disk."

References Cited UNITED STATES PATENTS 2,392,793 1/1946 Wood 112-220 H. HAMPTON HUNTER, Primary Examiner I vs. o1. X.R. I

UNITED STATES PATENT O-FFIC'E CERTIFICATE OF CORRECTION Patent No. 3,492,959 February 3, 1970 Herbert Wenz et a1.

It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as show below:

Column 4, line 14, "disk" should read part Signed and sealed this 17th day of November 1970.

(SEAL) Attcst:

Edward M. Fletcher, Jr. WILLIAM E. SCHUYLER, JR.

Commissioner of Patents Attesting Officer 

